Rare in Montana, where it is currently known from a few scattered sites in mountainous areas across the southern half of the state. Additional data on population levels are needed. Survey of suitable habitats will likely document additional occurrences.

General Description

Steven's Norwegian sedge is a loose clump-forming perennial with flowering stems up to 30 cm tall arising from a slender short-creeping rootstock. Flat, stiff, erect leaves, 2-4 mm wide, are clustered along the bases of the stems, and dried leaves of the previous year are conspicuously retained. The flowering stems are triangular, much taller than the leaves, and are rough to the touch above. Three to five cylindical spikes are borned on short stalks along the top of the stem, subtended by a leaf-like bract. The perigynia are subtended by dark-colored scales with obtuse tips and transluscent margins. The terminal spike is bisexual with female flowers above male flowers and the lateral spikes are unisexual, with only female flowers. At maturity the perigynia are longer than the scales, about 2.5 mm long, elliptical shaped with a short toothed beak, greenish becoming brown with age, and smooth or with inconspicuous bumps on the surface. Each perigynium has 3 styles and a 3-sided achene.

Phenology

Fruiting in July-August.

Diagnostic Characteristics

Carex stevenii belongs to a group of related species that are distinguished by well developed basal leaves, more than one spike, the lateral spikes with only female flowers, perigynia lacking hairs, and pistils with 3 style branches. It is distinguished from other members of this group by having short cylindrical rather than long cylindrical or oblong spikes. It is distinguished from Carex norvegica subsp. inserrulata by having spikes on short flowering stalks, many male flowers at the base of the terminal spike, and a perigynium surface that is smooth or nearly so. A hand lens and technical key are needed for positive identification.